Fosroc Conplast SP440M
High-range water-reducing, slump-retaining superplasticiser for flowing, pumpable and high-performance concrete — supplied and supported by Space Arc Engineering, your authorised Fosroc distributor across Delhi NCR and Pan-India.
What is it?
A chloride-free, high-range water-reducing superplasticising admixture from Fosroc’s Conplast SP440 family, formulated as a brown liquid blend of organic polymers that disperses cement particles to give up to 25% water reduction while retaining workability for extended periods.
Where is it used?
Ready-mix and site-batched concrete for high-rise structures, bridges, infrastructure, precast yards, raft and pile foundations, water-retaining structures and any pour requiring long-haul pumpability or flowing concrete in Indian site conditions.
Why use it?
It lets you cut mixing water sharply for higher strength and lower permeability, or hold slump over long transit and placing times, without sacrificing cohesion — improving durability, finish and pumping efficiency in one admixture.
How is it applied?
Dispensed into the concrete mix at the batching plant or transit mixer at 0.5%-1.2% (up to 1.5%) by weight of cement, added to the gauging water or to the mixed concrete; never to dry cement or aggregates.
About Fosroc Conplast SP440M
Fosroc Conplast SP440M belongs to the Conplast SP440 family of high-range water-reducing superplasticisers, engineered for concrete that must stay workable far longer than an ordinary plasticiser allows. Supplied as a brown, free-flowing liquid that is instantly dispersible in water, it is a blend of organic polymers (a sulphonated-naphthalene type chemistry) that wraps and disperses cement grains, releasing the water normally trapped between flocculated particles. The practical result is two modes of use from a single product: either take advantage of the dispersion to remove up to 25% of the mix water for a stronger, denser, less permeable concrete, or keep the water and gain a fluid, easily placed and pumped mix that holds its slump through long transit. The ‘M’ designation marks the slump-retaining grade of the SP440 line, formulated for the long haul-and-place cycles typical of Indian ready-mix supply, congested high-rise pours and infrastructure work where concrete may sit in a transit mixer for an hour or more before discharge. Conplast SP440M is chloride-free, so it is safe in reinforced and prestressed concrete, and it does not initiate corrosion of embedded steel. It entrains only about 1% additional air, so it improves cohesion and reduces bleeding and segregation without the strength penalty of an air-entrainer. For contractors, consultants and procurement teams in India, it sits in the practical middle ground between a conventional SNF superplasticiser and a premium polycarboxylic-ether (PCE) admixture: more slump life and water reduction than a basic plasticiser, at a cost and robustness that suit everyday structural and infrastructure concrete. Space Arc Engineering supplies Conplast SP440M as an authorised Fosroc distributor and applicator, with trial-mix support, dosage optimisation and logistics across Delhi NCR and Pan-India.
The technical insight
The performance of Conplast SP440M comes from electrostatic dispersion. In fresh cement paste, charged cement grains flocculate and lock pockets of mixing water inside the clusters. The sulphonated organic polymer in SP440M adsorbs onto the grains and imparts a like charge, so the particles repel each other, break the flocs apart and release that trapped water as additional lubrication. That mechanism is what allows up to 25% water reduction at constant workability. Where you bank the water reduction, the lower water-cement ratio translates into roughly 20% higher long-term strength and meaningfully reduced permeability and capillary porosity — the durability lever that matters most for water-retaining and aggressive-exposure structures. Where you keep the water, you get flowing, self-levelling concrete that needs minimal compaction. The slump-retaining (‘M’) formulation is tuned so that dispersion continues to release over time rather than all at once, which is why it holds workability through long transit instead of suffering rapid slump loss. Early-strength gains of 40-50% are achievable when the water reduction is fully exploited, useful for precast de-moulding and fast-cycle work. Because the additional entrained air is only around 1%, density and strength are preserved. Note that SP440M is sensitive to over-dosing — beyond the recommended ceiling it can cause retardation and bleeding — so site verification by trial mix with the actual cement, aggregates and ambient temperature is essential, as performance shifts with cement chemistry (it suits all cements except high-alumina cement) and with the order of addition.
Where it is used
- High-rise and multi-storey RCC where concrete must remain pumpable to upper floors
- Ready-mix concrete (RMC) requiring extended slump retention over long transit and queuing times
- Flowing concrete for heavily reinforced or congested sections needing little or no vibration
- Pumped concrete over long horizontal and vertical distances
- Raft, pile cap and mass-foundation pours where placing and compaction time is extended
- Water-retaining structures, basements and tanks where low permeability is critical
- Precast and prestressed elements where chloride-free high early strength speeds de-moulding
- Bridge decks, piers and infrastructure concrete in hot Indian ambient conditions
- High-strength and high-performance concrete (M40 and above) at reduced water-cement ratio
Key advantages
- High water reduction of up to 25% at constant workability for stronger, denser concrete
- Extended slump retention reduces re-tempering and waste during long-haul ready-mix supply
- Chloride-free formulation safe for reinforced and prestressed concrete
- Improves cohesion and minimises segregation and bleeding for better surface finish
- Up to ~20% higher ultimate strength and 40-50% higher early strength when water reduction is exploited
- Reduced permeability and porosity improve durability and resistance to aggressive environments
- Compatible with all cement types except high-alumina cement
- Only ~1% additional air entrained, so strength and density are preserved
- Produces flowing, easily pumped concrete that needs minimal compaction
- Long 12-month shelf life simplifies site stocking and procurement
Limitations & considerations
- Over-dosing beyond the recommended range can cause excessive retardation, bleeding and segregation
- Not compatible with high-alumina cement
- Slump life and water reduction vary with cement source, mix temperature and aggregates — trial mixes are essential
- Liquid drums require protection from frost and direct sunlight and have a finite 12-month shelf life
- As an SNF-type admixture it delivers less ultra-high water reduction and slump life than premium PCE superplasticisers
- Must be added to gauging water or mixed concrete, never to dry cement — incorrect dispensing reduces performance
- Performance depends on accurate, calibrated dosing; manual on-site addition risks inconsistency
- Not a substitute for sound mix design, curing or waterproofing — it reduces permeability but is not a standalone waterproofing system
Selection & best practice
Always confirm the optimum dosage by laboratory and site trial mixes using the actual cement, aggregates, fly ash/GGBS and ambient temperature for the project, rather than assuming a fixed figure. Start near the middle of the 0.5%-1.2% by weight of cement range and adjust to hit the target slump, slump-retention time and water-cement ratio, keeping below the 1.5% ceiling to avoid retardation and bleeding. Add Conplast SP440M to the gauging water or to the freshly mixed concrete and mix thoroughly for even dispersion; never add it to dry cement or aggregates. Use calibrated automatic dispensers at the batching plant for dosing accuracy. For long pumping runs or hot-weather pours, plan the dose around the actual haul-plus-placing time so slump is retained to the point of discharge. Store drums under cover, protected from frost and direct sun, and use within the 12-month shelf life. For projects also needing surface-applied or integral waterproofing, structural repair or curing, pair it with the appropriate Fosroc system rather than over-dosing the admixture. Space Arc Engineering provides trial-mix support and dosage optimisation as part of supply.
Specifications
| Product family / type | Conplast SP440 family — high-range water-reducing, slump-retaining superplasticiser |
| Chemical base | Blend of organic polymers (sulphonated naphthalene / SNF type) |
| Form & colour | Liquid, brown; instantly dispersible in water |
| Specific gravity | Approx. 1.22 to 1.25 (typical for SP440 family; confirm on batch TDS) |
| pH at 27°C | 7.0 to 8.0 |
| Chloride content | Nil (to IS 456 / BS 5075) |
| Water reduction | Up to 25% at constant workability |
| Air entrainment | Approx. 1% additional air entrained |
| Dosage (typical) | 0.5% to 1.2% by weight of cement; up to 1.5% for specific mixes |
| Strength gain | Up to ~20% ultimate; ~40-50% early strength when water reduction is used |
| Cement compatibility | All cements except high-alumina cement |
| Standards | IS 9103:1999; ASTM C494 Type D & Type G; BS 5075 Part 3 |
| Pack size | 200 litre drums (also supplied in barrels by weight) |
| Shelf life | Minimum 12 months in unopened containers under normal storage |
Industry use cases
Ready-Mix Concrete (RMC)
Holds workable slump through long plant-to-site transit and on-site queuing, cutting re-tempering, rejected loads and water addition at the pump — critical for Delhi NCR’s congested-traffic deliveries.
High-Rise Construction
Keeps concrete fluid and pumpable to upper floors and through congested reinforcement, enabling clean placement with minimal vibration in columns, cores and slabs.
Infrastructure & Bridges
Allows extended placing and compaction time on large pours such as bridge decks, piers and pile caps, while the reduced water-cement ratio improves durability in exposed conditions.
Precast & Prestressed Yards
Chloride-free chemistry with high early strength supports faster de-moulding and production cycles for beams, panels and prestressed elements.
Water-Retaining & Underground Structures
Low water-cement ratio and reduced permeability help produce dense, low-porosity concrete for tanks, basements and STPs where watertightness is essential.
High-Strength / HPC Mixes
Enables M40-and-above grades at low water-cement ratios for demanding structural concrete without losing placeability.
Frequently asked questions
What is Fosroc Conplast SP440M used for?
What is the recommended dosage of Conplast SP440M?
Is Conplast SP440M chloride-free and safe for reinforced concrete?
Which standards does Conplast SP440 comply with?
How is SP440M different from Conplast SP430?
What is the shelf life and pack size?
How we position Fosroc Conplast SP440M
Conplast SP440M sits in the practical, value-engineered tier of the concrete admixture market — an SNF-based superplasticiser that delivers genuine slump retention and up to 25% water reduction without the premium cost of a polycarboxylic-ether (PCE) product. Within the Fosroc range it complements Conplast SP430 and SP430 G8 (high-early-strength water-reducers/retarders), Conplast SP500-series PCE superplasticisers for ultra-high-performance and self-compacting concrete, and integral waterproofers such as Conplast X421 IC / Conplast WL; for surface waterproofing or repair you would pair it with systems like Brushbond, Nitobond or Renderoc rather than over-dosing the admixture. Against competitors, it is comparable to Sika’s SNF-based plasticisers (the Sika Plastiment / Sikament family) and is positioned below Sika ViscoCrete PCE admixtures on water reduction and slump life; in the Indian market it competes with MBS (formerly BASF Master Builders) MasterRheobuild and MasterGlenium ranges, and with mid-tier offerings from Dr. Fixit (Pidilite) and STP (Sika-STP / CICO) for everyday structural concrete. For a contractor or RMC producer who needs reliable, long-slump, pumpable concrete at sensible cost across Indian conditions, SP440M is a sound default; for very low water-cement ratios, self-compacting concrete or extreme slump-life demands, step up to a PCE-based product such as the Conplast SP500 series. Space Arc Engineering, as an authorised Fosroc distributor and applicator in Delhi NCR and Pan-India, can supply SP440M alongside the right complementary Fosroc systems and provide trial-mix and dosage support to match the admixture to your specific mix and project.
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